Bicycle seat post



Filed May 21 1923 2 Sheets-Sheet 1 U n w u.

March 24, 1925.-

1,530,705 C. TIBBOTT YQ E m rq Filed May 21. 1923 2 Shoots-Sheet 2 Zip". .[0

- 736%? Ja a HTZOEAVAZHJ Patented Mar. 24, 1925.

' UNiTED' STATES 7 1,530,705 PATENT ore-ice- CHARLES riteno'r'r, or LAKEVZOOD, onto.

BICYCLE SEAT POST.

. Application filed May 21,

To allauhom it may concem:

Be it known that I,CHARLES,TIBBOTT, a citizen of the United States, residing at Lakewood, in the-county of Cuya-hoga and State of Ohio, have invented a. certain new and useful Improvement in Bicycle Seat Posts, of which the following is a full, clear, and exact description, reference being'had to the accompanying drawings.

My invention has forits object the production of a tubular supporting angle member, particularly adapted for use as a. bicycle seat post, that is stronger and less liable to breakage, and capable of being more cheaply manufactured, than existing articles of this class.

Heretofore it has been the p'acticein the production of the better grade of bicycle seat posts to weld a solid forging comprising the upper angle portion of the post to a tubular stem portion adapted to be inserted in the inclined tubular socket of the bicycle frame. The normally horizontal portion of such forging, adapted to accommodate the clamping means on the saddle, is of suiii cient size and strength when made with a relatively small diameter and isordinarily enlarged at the angle to form a short inclined solid stub of a diameter equal to that of the tubular stem to which it is welded,

and which necessarily has an exterior diameter no greater than the interior diameter of the bicycle frame tubing in which such stem is adapted to be clamped. This forging is, of course, more expensive than tubing, and partly on account of the size limitations, a suflici-ently strong joint between the solid forging and the tube is diiiicult to secure, and moreover constitutes the weak spot in the finished article.

My invention comprises an improved ticle of this class. and an improved method for its manufacture. Instead of welding a forging having a reduced end to a separate tubular stem, I find a stronger seat post may be made at less cost by using one piece length of tubing. with or without reinforcing means depending upon'the gauge of tubing employed and the strength desired. The saddle clamp engaging portion or arm of lesser diameter than the stem is thenformed by swaging one end to a thiclrer gauge. The tube is then bent at the proper angle adjacent to the taper formed between the swaged and unswaged portions, to form the completed article.

a. n length OI tubing of heavier gauge, requiring 1923. Serial No. 640,372.

The invention is hereinafter more fully bodiments of the invent-ion, Fig. 1 is an ele- J vation of a length of tubing of proper dimensions to constitute a bicycle seat post; Fig. 2 is a central longitudinal section through such tubing showing a tubular reinforcing member positioned in one end; Fig. 3 is an elevation of the tube after one end portion has been swaged to reduced diameter; Fig. & is an elevation of the finished post after being bent forwardly at the proper angle; Figs. 5 and 6 are transverse sections on the corresponding lines of Fig. i; is a longitudinal section through a no reinforcement Fig. 8 is an elevation of thesame after it has been swaged; Fig. 9 is an elevation of the same after it has been bent rearwardly to form a different type of seat post; and Figs. 10 and 11 are transverse sections on the corresponding lines of Fig. 9.

As shown in Figs. 1 to 6, 10 designates a length of steel tubing of a diameter to fit within the tubular frame of the bicycle for which the finished seat post is adapted 'to-be used. The walls of such tube 10 may be comparatively thin being referably of #17 gauge, The length, of course, will vary according to the length of post to be made; a very popular size being made from 9 inches of tubing. Reinforcing tubing 20 which may satisfactorily comprise a 5" length of stock in diameter and #12 gauge, is fitted at one end. The tubing thus reinforced is then swaged to form the normally horizontal saddle engaging portion of the finished seat post, as designated by the numeral 21, the length of the swaged portion being roughly 8 inches. The junction between such portion and the unswaged portion'22 constituting the stem of the post, comprises the tapered portion 24, approxiniately one inch in length. During such swaging process, the diameter of the portion 21, is reduced ordinarily to the standard size of the opening 25, within the tube 20 being also reduced in size as shown at 26. The portion or arm 21, is then bent preferably about a radius to theproper angle to constitute the saddleengaging portion of the post which should be horizontal when the stem portion 22 is fixed within the frame of the bicycle. In the type of post illustrated in Fig. 4 the angle between the arms is substantially 7 3. After bending, the surface of the completed post may be finished in any desired manner.

A modified form of construction, as also a different type of seat post, is illustrated in Figs. 7 to 11. In this embodiment of my invention a section of tubing 30, which may be of the same length and diameter, but preferably of heavier gai i ge (#12 being satisfactory) is employed. W'ieh stock of such gauge no reinforcing is necessary. 7.

The tube is swaged to form the saddle engaging portion of {the seat post as in the embodiment first described. Since the thickness of the tube 30 is less, however,

' than the combined thickness of the tubes 10 opening 'and adapted to extend rearward-1y and horizontally when the stem portion is fixed Within the bicycle frame to form a post adapted for use when it is desired to mount the saddle in a more rearward position relative to the frame than is possible vvit h the typeillustrated in 4. A further bending Would be effected to produce the type of post shown in Fig. 4E.

It will be apparent that my angle post 35 i process such stock may be shaped-and rein- :c'orced at a single operation and without waste, thus avoidin the *di fiiculties "incident to the production of the welded product. I have found in actual "test that my construe tion will Withstandsubstantially twice as great a load before "breaking as ordinary seat post comprising a forging Welded to a tubular stein.

Having described claimz V 1. An angle post comprising a tubular member having its arms of difle'rerit diame- 'ter and gauge, and connected by a tapered portion.

2. A bicycle seat post, tubular "t'hiongl'r out its length, having a stem portion and a my I invention, 1

saddle engaging portion of diflei-entdiameter and gauge, said portions being-integrally connected by a tapered portion.

In testimony Whereo'f,l hereunto ath x my signature.

CHARLES TIBBoT'r. 

